Lock



FIG. 1 is a top, front, right side perspective view of a lock showing our new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The long dash-short dash broken lines in the figures represent boundaries of the claimed design and form no part thereof. All other broken lines illustrate portions of the lock that form no part of the claimed design. 

CLAIM The ornamental design for a lock, as shown and described. 